/*
 * Licensed to Crate under one or more contributor license agreements.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.  Crate licenses this file
 * to you under the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.  You may
 * obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial
 * agreement.
 */

package io.crate.metadata;

import org.elasticsearch.cluster.metadata.Metadata;
import org.elasticsearch.common.settings.Settings;

import java.util.Iterator;
import java.util.Map;
import java.util.ServiceLoader;
import java.util.function.UnaryOperator;

public class CustomMetadataUpgraderLoader implements UnaryOperator<Map<String, Metadata.Custom>> {

    private final Settings settings;
    private final Iterator<CustomMetadataUpgrader> upgraders;

    public CustomMetadataUpgraderLoader(Settings settings) {
        this.settings = settings;
        upgraders = ServiceLoader.load(CustomMetadataUpgrader.class).iterator();
    }

    @Override
    public Map<String, Metadata.Custom> apply(Map<String, Metadata.Custom> metadataCustoms) {
        while (upgraders.hasNext()) {
            upgraders.next().apply(settings, metadataCustoms);
        }
        return metadataCustoms;
    }
}
